JPH0446824Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a spray gun, and in particular, a structure of a spray gun that can effectively improve the finished state of a painted surface when used for air spray painting. It is related to.

(Prior Art) Air spray painting, as is well known, is also called spray painting or spray painting, in which a specified paint is atomized into a mist using compressed air. This is a coating method that is applied by spraying onto the painted surface, and because of its high efficiency and excellent uniformity of the coating, it has been widely used in various fields such as architectural coating and mechanical coating. There is.

Incidentally, such air spray painting equipment usually has a structure in which a specified liquid paint is atomized and ejected by the jetting action of compressed air guided from a specified air compressor at its nozzle part. A spray gun is used.

Therefore, when painting using such a spray gun, the paint sprayed onto the object to be coated is
Since it is sprayed together with compressed air, the cleanliness of the compressed air has a great effect on the finished state of the coating. That is, if such compressed air contains water droplets, the water droplets adhere to the surface to be coated, causing the sprayed paint to be repelled and pinholes to be caused in the formed paint film. Furthermore, dust contained in the compressed air adheres to the painted surface, causing problems such as so-called bumps and roughness of the paint film.

Therefore, in addition to preventing deterioration of the paint finish due to impurities contained in compressed air,
In order to prevent the performance and durability of the spray gun from deteriorating due to such impurities, one or more air compressors are usually installed on the air line connected to the air compressor to supply compressed air to the spray gun. A plurality of air filter devices are provided, and the air filter devices collect and remove impurities such as moisture, oil, and dirt contained in the compressed air, and provide clean air to the spray gun. It is designed so that it can be supplied.

(Problem) However, while such an air filter device is installed on a fixed air line, a hose made of an elastic material such as rubber is used to connect the fixed air line to a spray gun. Because the process requires a relatively long time, it is unavoidable that the distance between the air filter device and the spray gun on the airline becomes long, and the above-mentioned problems have not been sufficiently solved. be.

That is, because the hose connected to the spray gun is long, there is a risk that moisture in the compressed air will condense within the hose and water droplets will be generated. These water droplets will be ejected together with the paint, so these water droplets will
This method has the problem of causing pinholes in the coating film formed.

(Solution) The present invention was developed against the background of the above-mentioned circumstances, and its purpose is to solve the problem of pinholes caused by air spray painting. To provide a spray gun which can effectively prevent this and obtain a painted surface with a good finish.

In order to achieve such an object, the present invention provides a spray gun as described above, which performs a predetermined painting operation by atomizing a predetermined paint from a tip nozzle by the jetting action of compressed air. The air passage in the grip part that leads air to the tip nozzle part is formed as a cavity large enough to accommodate a breathable cartridge containing a predetermined filler, and the compressed air led from the outside is After passing the cartridge set in the
It is arranged so that it is immediately guided to the tip nozzle section.

(Function/Effect) In other words, in the spray gun having the structure according to the present invention, water droplets contained in the compressed air supplied to the spray gun are removed by the compressed air guided through the hose from the supply source such as the compressor. is vaporized by expansion within the air passages of its body and can be effectively removed when passing through the interior of a cartridge disposed within such air passages, and such water droplets are removed. The compressed air is immediately ejected from the nozzle at its tip along with the predetermined paint.

Therefore, in the case of a spray gun having such a structure, even if the supplied compressed air contains water droplets, the water droplets will not be ejected as they are from the nozzle portion; The occurrence of pinholes in the paint film can be effectively prevented, and a painted surface with a good finish can be obtained.

(Example) In order to clarify the present invention more specifically, an example having a structure according to the present invention will be described in detail below with reference to the drawings.

First, the drawings show a spray gun 10 according to an embodiment of the present invention.

This spray gun 10 is a cup-type suction type spray gun, and inside thereof, there is an air passage leading from the air supply port 16 of the connection cap 14 attached to the lower part of the grip part 12 to the ejection hole of the nozzle part 18. It has 20. As shown in the figure, the air passage 20 has an enlarged-diameter portion 22 at a predetermined length from the opening toward the back of the grip portion 12, and has a male thread groove on its outer circumferential surface. A bottomed cylindrical connection cap 14 having an air supply port 16 to which a predetermined compressed air supply hose 34 is connected at the center of the bottom thereof is connected to the opening of the enlarged diameter portion 22 formed as a cylindrical protrusion. By screwing together and closing the opening of the enlarged diameter portion 22, a cartridge accommodating space of a predetermined size is formed.

In the cartridge housing space (expanded diameter portion 22), a cylindrical cartridge 30 is formed by housing a predetermined filling material 28 made of a material such as cotton in a cylindrical housing 26 made of metal or resin. has been inserted and placed. This cartridge 30 has ventilation holes 24 and 25 of a predetermined size in the walls that close both ends in the axial direction, respectively.
It has the function of filtering impurities such as water droplets and dust contained in the compressed air that is passed through the inside using a filler 28 that is housed inside. A structure as shown in FIG. 1 is preferably used. Further, in the cartridge 30, the outer diameter of the cap portion constituting the end wall at one end in the axial direction is larger than that of the main body, and a flange portion 32 extending in the axial direction is provided at the outer peripheral edge of the cap portion. The flange portion 32 is housed in a state where it is firmly sandwiched between the opening end face of the enlarged diameter portion 22 and the connection cap 14 at both axial ends thereof. An annular sealing member 42 is disposed on the inner bottom surface of the connection cap 14 at a portion that comes into contact with the end surface of the flange portion 32, thereby sealing the open end of the flange portion 32. It is sealed from the outside, and compressed air supplied from the air supply port 16 of the connection cap 14 is guided to the ejection hole of the nozzle portion 18 via the cartridge 30.

The communication state of compressed air supplied from the air supply port 16 and reaching the ejection hole of the nozzle portion 18 via the cartridge 30 can be interrupted or interrupted by the reciprocating operation of the air valve 38 based on the operation of the operating lever 36. In the communicating state, a predetermined liquid paint contained in a paint cup 40 attached to the spray gun 10 is atomized at the nozzle part 18 by the jetting action of the compressed air. Spray painting can be performed by ejecting from an ejection hole provided at the tip of the nozzle portion 18.

Therefore, in the spray gun 10 having such a structure, even if water droplets are included in the compressed air supplied from the air supply port 16, the water droplets will not be absorbed by the compressed air when the compressed air enters the air passage 20. It is vaporized by the volume expansion when introduced into the enlarged diameter part 22, and is absorbed by the filler 28 of the cartridge 30 housed in the enlarged diameter part 22, and then evaporated as entrained vapor. In addition, from the cartridge 30 to the nozzle part 1
Since the air passage 20 leading to the nozzle no. 8 can be effectively formed short, it is possible to effectively prevent evaporated water from condensing and forming water droplets in the air passage 20.

Further, impurities such as dust contained in the compressed air can also be removed by the cartridge 30, and therefore, water droplets, dust, etc. can be removed from the compressed air that is ejected from the jet hole of the nozzle part 18 together with the paint. It does not contain impurities, and the occurrence of pinholes, bumps, etc. on the resulting painted surface can be effectively prevented, and a painted surface with a good finish can be obtained.

Furthermore, the cartridge 30 in this embodiment
is formed by accommodating the filling material 28 in the housing 26, and therefore, the filling material can be replaced extremely easily by replacing the cartridge 30.
By replacing the cartridge in this manner, the above-described effects of the spray gun can be maintained in a good manner.

Above, one embodiment of the structure according to the present invention has been described in detail with reference to the drawings.
This is a literal illustration, and the present invention should not be construed as being limited by such a specific example.

For example, in the above embodiment, the present invention was applied to a cup-type suction type spray gun, but the present invention can also be applied to other gravity-type spray guns or paint pressure-feeding type spray guns. The present invention can also be well applied to guns, and the effects shown in the embodiments described above can be effectively achieved in such products as well.

Furthermore, the present invention has a major feature in that a cartridge capable of removing water droplets is disposed within the air passage provided in the main body of the spray gun, thereby achieving the excellent effects described above. Therefore, the cartridge used in the present invention is not limited to the structure shown in the above embodiment, and is arranged in a compressed air passage and contained in the compressed air. Any material may be used as long as it has the function of removing water droplets, and its shape and filler material may be changed as appropriate. For example, the cartridge may be formed so that its cross section is rectangular or elliptical. It is also possible to form such a cartridge without a flange.

Although not listed in detail, the present invention may be implemented with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, and such embodiments may be implemented in accordance with the present invention. It goes without saying that any of these are included within the scope of the present invention as long as they do not deviate from the gist of the invention.

[Brief explanation of the drawing]

The attached drawing is a partially cutaway sectional view showing an embodiment of the present invention. 10...Spray gun, 12...Grip part,
16... Air supply port, 18... Nozzle part, 20...
... air passage, 22 ... enlarged diameter section, 28 ... filler,
30... Cartridge.

Claims (1)

[Scope of Claim for Utility Model Registration] In a spray gun that performs a prescribed painting operation by atomizing a prescribed paint by jetting compressed air from a tip nozzle, a grip section that guides air to the tip nozzle. The air passage is formed as a cavity large enough to accommodate a breathable cartridge containing a predetermined filler, and compressed air introduced from the outside is allowed to pass through the cartridge set in the cavity. The spray gun is configured such that the spray gun is immediately guided to the tip nozzle portion after the spray gun is sprayed.